1. Field of the Invention
This invention is directed to drilling rigs; drilling rigs with an erectable mast; and to methods for erecting such a mast.
2. Description of Related Art
The prior art discloses a variety of rigs used in drilling and wellbore operations and methods of rig assembly; for example, and not by way of limitation, rigs and assembly methods as disclosed in U.S. Pat. Nos. 2,857,993; 3,340,938; 3,807,109; 3,922,825; 3,942,593; 4,021,978; 4,269,395; 4,290,495; 4,368,602; 4,489,526; 4,569,168; 4,821,816; 4,831,795; 4,837,992; 6,634,436; 6,523,319; 6,994,171; 7,306,055; 7,155,873; and 7,308,953 and the references cited in these patents—all these patents incorporated fully herein for all purposes.
In many drilling operations, drilling rigs and related systems, equipment, and apparatuses are delivered to a site, assembled and then disassembled. It is important that drilling rigs and their components be easily transported and assembled. Costs associated with land rigs and associated equipment, can be calculated on a per hour or per day basis, and, therefore, efficient assembly, takedown, transport, and setup operations are desirable.
U.S. Pat. No. 3,922,825 discloses a rig with a stationary substructure base and a movable substructure base mounted thereon which is coupled to the stationary base and swings upright into an elevated position on a series of struts that are connected to the stationary base with swivel connections at each end. The movable base is otherwise stationary since neither the stationary base nor the movable base are mobile or repositionable without the use of an auxiliary crane or the like. The movable substructure base and the drill mast are raised with a winch mounted on an auxiliary winch truck.
U.S. Pat. No. 3,942,593 discloses a mobile well drilling rig apparatus which has a trailerable telescoping mast and a separate sectionable substructure assembly with a rig base, a working floor, and a rail structure. The mast is conveyed to the top of the substructure by rollers and is raised by hydraulic raising apparatus to an upright position. With such a system the the mast assembly can be relatively long when transporting it and the mast can be unstable during raising. This system uses drawlines and winch apparatus to raise the mast onto the working floor.
U.S. Pat. No. 4,021,978 discloses a telescoping mast assembly adapted for use with drill rigs and the like. The mast assembly has multiple sections, said sections being adapted for nesting one within the other in the telescoped-to-the-closed condition and each section has mutually convergent corner leg members which, when the mast assembly is extended, form concentric and in-line arrangements of the corner leg members from the base to the crown of the mast. Means are provided for connecting each mast section to its neighboring mast section upon extension thereof. In addition, means are also provided for indexing of the connector means upon extension of the mast assembly from its telescoped-to-the-closed condition.
U.S. Pat. No. 4,821,816 discloses methods of assembling a modular drilling machine which includes a drilling substructure skid which defines two spaced parallel skid runners and a platform. The platform supports a draw works mounted on a draw works skid, and a pipe boom is mounted on a pipe boom skid sized to fit between the skid runners of the drilling substructure skid. The drilling substructure skid supports four legs which in turn support a drilling platform on which is mounted a lower mast section. The legs are pivotably mounted both at the platform and at the drilling substructure skid and a pair of platform cylinders are provided to raise and lower the drilling platform. A pair of rigid, fixed length struts extend diagonally between the platform and the substructure skid away from the platform such that the struts do not extend under the platform and obstruct access to the region under the platform. The pipe boom skid mounts a pipe boom as well as a boom linkage, a motor, and a hydraulic pump adapted to power the pipe boom linkage. The substructure skid is formed in upper and lower skid portions, and leveling rams are provided to level the upper skid portion with respect to the lower skid portion. Mechanical position locks hold the upper skid in relative position over the lower skid. In one aspect such a method for assembling an earth drilling machine includes the steps of: (a) providing a modular earth drilling machine comprising a drilling substructure skid, a draw works skid, and a pipe boom skid, the drilling structure skid having a collapsible drilling substructure platform and means for receiving the draw works skid and the pipe boom skid, the draw works skid having a draw works winch, and the pipe boom skid having a pipe boom pivotably mounted to the pipe boom skid for rotation about a pivot axis, at least one hydraulic cylinder coupled between the pipe boom and the pipe boom skid to rotate the pipe boom about the pivot axis, a hydraulic pump mounted to the pipe boom skid and coupled to the hydraulic cylinder by a closed hydraulic fluid circuit, and a pipe boom skid winch; the pipe boom skid, pipe boom, hydraulic cylinder and hydraulic pump forming a modular unit which is transportable as a single unit without any disconnection of the closed hydraulic fluid circuit; (b) positioning the substructure skid at a desired drilling position; (c) utilizing the pipe boom skid winch to pull the pipe boom skid into position with respect to the substructure skid; (d) utilizing the pipe boom skid winch to pull the draw works skid into position with respect to the substructure skid; and, in one aspect, the method further including raising the collapsible drilling structure platform, including utilizing the pipe boom skid winch to lift the drilling structure platform during at least an initial stage of the raising step.
U.S. Pat. No. 4,831,795 discloses drilling derrick assemblies which provide for the elevation above ground level of the assembly's working floor which supports both the mast and the drawworks. Prior to erection, the elevatable equipment floor is carried on a supporting substructure, and a mast is pivotally connected to the elevatable floor in a reclining position. When the assembly is erected, the mast is pivotally raised and attached in place, and other rigging steps can be carried out. Through the use of an integrally mounted sling and winch assembly or, alternatively, through operation of the assembly's traveling block, the entire equipment floor is elevated to the desired level. In one aspect, a drilling structure is disclosed that has: a substructure for supporting the drilling structure on the surface through which drilling is to occur, an elevatable floor assembly which rests on the substructure in its lowered position, a reclining mast pivotally connected to the elevatable floor, a gin pole assembly mounted on the elevatable floor assembly rearwardly of the point at which the mast is pivotally connected to the elevatable floor and arranged to receive line for raising the mast, whereby the mast is raised prior to raising the elevatable floor assembly, a collapsible vertically standing elevating frame assembly mounted on the substructure and forwardly of the mast, when raised, and the forwardmost end of the elevatable floor assembly, winch means rotatably mounted in and arranged adjacent the forwardmost end of the substructure, a first elevating block means mounted in the elevatable floor and rearwardly of the elevating frame assembly, a second elevating block mounted on the elevating frame assembly at a vertical point corresponding with the level to which the elevatable floor is to be raised, an elevating line extending from the winch means and reeved about the elevating block so that motion of the winch means in one direction causes the second elevating block to move toward the first elevating block raising the elevatable floor vertically and forwardly, motion of the winch means in another direction lowering the elevatable floor vertically and rearwardly, and a brace member on each side of the drilling structure, each brace member being pivotally connected at its ends, respectively, to the substructure and the elevatable floor, the brace members being arranged in pairs forming parallel linkages thereby causing the elevatable floor assembly to be raised in an arc-like motion.
U.S. Pat. No. 6,994,171 discloses two section masts with self-aligning connections and methods with self-aligning connections for a two section mast. The methods include the steps of transporting the elongated bottom mast section to a guide frame adjacent to a well site, the bottom mast section having a pair of front legs and a pair of rear legs. An elongated top mast section is transported to the well site, the top mast section having a pair of front legs and a pair of rear legs. The legs of the bottom mast section are positioned slightly below a level of the legs of the top mast section. Thereafter, the bottom mast section is raised slightly to order to engage the top mast section while simultaneously aligning the mast sections together. The sections are thereafter pinned together. In one method of self-aligning connections for a two section mast, the method includes: transporting an elongated bottom mast section to a guide frame adjacent to a well site, the bottom mast section having a pair of front legs and a pair of rear legs so that the bottom mast section is in a substantially horizontal orientation; thereafter transporting an elongated top mast section to the well site so that the top mast section is in a substantially horizontal orientation and so that the mast sections are substantially aligned lengthwise, the top mast section having a pair of front legs and a pair of rear legs; positioning the legs of the bottom mast section slightly below a level of the legs of the top mast section; raising the bottom mast section; and simultaneously engaging and guiding the mast sections together in a final connecting orientation.
U.S. Pat. No. 7,155,873 discloses structural connectors for a drilling rig substructure; and a method and apparatus for connecting sections of a drilling rig substructure, in one aspect a structural connector is provided so that sections of a drilling rig substructure can be connected together without the use of pins or pin-type connectors. The structural connector utilizes specially-shaped fixed members connected to, and extending through, support plates that are attached to sections of a drilling rig substructure that mate with specially-shaped mating lugs that are mounted on mating lug plates that are attached to separate sections of the drilling rig substructure. When the sections of the drilling rig substructure to be connected are positioned together, the specially-shaped mating lugs engage the specially-shaped fixed members and form a high strength structural connection between the sections of the drilling rig substructure. In one aspect a structural connector is provided that has: a plurality of support plates each having a plurality of fixed support members extending therethrough, the fixed support members extending outwardly from both sides of the support plates and having side walls and contoured tops; a mating lug assembly having a plurality of mating lug plates and a plurality of mating lugs attached to each mating lug plate, each mating lug having a support notch therein; wherein the support notch of each mating lug has tapered guide surfaces at the entry point of the support notch, side walls, and a contoured top.